1. Field of the Invention
The present invention relates generally to healing of wounds and wound-treatment therapies. More particularly, but not by way of limitation, the present invention relates to fluid-instillation and negative-pressure wound therapies.
2. Background Information
Clinical studies and practice have shown that providing therapeutic fluids, particularly in conjunction with reduced pressure, in proximity to a tissue site augments and accelerates the growth of new tissue at the tissue site. The applications of this phenomenon are numerous, but application of reduced pressure has been particularly successful in treating wounds. This treatment (frequently referred to in the medical community as “negative pressure wound therapy,” “reduced pressure therapy,” or “vacuum therapy”) provides a number of benefits, including faster healing and increased formulation of granulation tissue. Typically, reduced pressure is applied to tissue through a wound insert (e.g., a porous pad or other manifold device). The wound insert typically contains cells or pores that are capable of distributing reduced pressure to the tissue and channeling fluids that are drawn from the tissue. The wound insert can be incorporated into a wound dressing having other components that facilitate treatment, such as, for example, a drape (e.g., adhesive surgical drape). Instillation fluids may be delivered to the wound insert and held in place at the site of the wound, further improving the efficacy of treatment.
Wound treatment systems, including for example, instillation therapy units such as the V.A.C. Ulta Therapy System, available from Kinetic Concepts, Inc., San Antonio, Tex. U.S.A. may be used to deliver fluids with a more pronounced therapeutic benefit than saline, and indeed, may expand in complexity and capability to be able to deliver a plurality of fluids for different purposes dependent upon wound conditions. It is believed that fluids will be able to be used to reduce infection, to aid with debridement, to improve the dressings removability and to address biofilm buildup in the wound.
Certain systems offer fluids with molecules which are tailored and effective to provide the benefits described the above, but often are not designed for use with a system which doses the fluid over time and exposes the fluid to tubing and other plastic components. For example, wound treatment fluids may contain an active molecule that reacts with various types of plastic and light (including, e.g., ultraviolet light), thus weakening the molecules effectiveness and making its practical delivery to the wound site more difficult.
It is therefore desirable in systems with molecules which may be susceptible to negative impacts of contact with certain materials or light to protect them or render them immune to these range of deleterious effects until the system determines they should be active.
As described herein, it is possible to provide for control of the stimulation or activation of fluids used in wound treatment systems.